1. Field of the Invention
The invention relates to a method for stapling sequential printed sheets positioned straddled one above the other on supports of a conveying apparatus and stapled on a stapling segment by stapling heads that rotate in tracks above the supports and cooperate with a bending apparatus with wire staples made of an endless wire. The invention further relates to an apparatus for executing the method for stapling printed sheets gathered straddled one above the other on supports of a conveying apparatus following one another with spacing, the apparatus comprising at least one stapling head pair that rotates in tracks above the supports and cooperates with the latter and a bending apparatus; the stapling head pair is configured by a bending apparatus that shapes a supplied wire segment into a staple, and a driver that forces the staple through the gathered printed sheets.
2. Description of the Related Art
An apparatus of this type is disclosed in, among other publications, CH-A-667,621. This apparatus includes a rotary stapler, in which the printed products are positioned by means of positioning stations to straddle the gathering segments disposed symmetrically around a rotational axis, and conveyed by carriers along the gathering segments to a work region of a stapling apparatus. The stapling heads of the stapling apparatus are allocated to the gathering segments, so that on every gathering segment loaded with printed products, stapling can take place at the end of the gathering region; to execute the stapling process, stapling apparatuses are used in which stapling heads coupled with gathering segments rotate, and are actuated to staple by stationary cam tracks, or in which the stapling heads are driven to be actuated to be driven over a martial region of the circumference of the drum-shamed gathering apparatus formed by the gathering segments.
As an alternative to this embodiment of rotating stapling heads, CH-A-667,621 discloses a stapling apparatus in which the rotational axis of the stapling heads is provided at a distance from or outside of the gathering segments disposed in a drum configuration.
The same applies for EP-A-0,399,317.
Rotary staplers of this type have a compact design; however, they are, not least of all because of their narrow design, susceptible to interferences that processing and make eliminating the pauses relatively time-consuming due to a lack of simple overview and accessibility.